Galton Blackiston, 56, joined James Martin, 47, on his Saturday Morning cooking show last week, alongside Sherlock star Amanda Abbington, 45.
During their chat, Galton pronounced the English town Swaffham in a Norfolk accent, before highlighting that some people mispronounce it.
The chef then gave an example of how other people pronounce the word, prompting James to have a go himself.
The star then pointed out how different people say the word samphire.
He said to his fellow chef: “It’s like samphire and samphoot,” prompting Galton to reply: “Well, yeah, that’s bang in season at the moment.”
Abbie then asked Galton how to pronounce samphire correctly.
He replied: “That’s a good question,” before pointing at James and adding: “Because listen to this idiot, he calls it all different things and he doesn’t call it what it should be called.”
As the pair continued cooking, James had a further two attempts at pronouncing the word before bringing the conversation back on to Norfolk.
Last month, the chef was joined by former James Bond Jane Seymour, 68, on the show.
During a chat with the actress, James Martin admitted he had googled her naked.
The conversation began when Nick Nairn, 60, told Jane he had been talking about the “amazing things” she has done in her career.
She replied: “The only way I remember anything is by looking at all the old photographs, so on my Instagram if I look at what the fans have put up, I find all these photographs that I’d forgotten about.”
“The fans have been putting stuff up recently,” James responded, before hesitantly adding: “Because you’ve done Playboy again.”
James then highlighted how she had been on the cover of the iconic magazine three times, prompting her to reply: “Yes, but I’ve never been naked.”
She then paused before adding: “I just hate to… you know.”
Smirking, James jokingly replied: “I checked it out on Youtube, I did check,” which prompted Jane to laugh.
She then explained: “I am very proud of the fact that I think it’s okay to be in you mid-sixties and show people that you’re very much still a woman. How’s that?”
James responded telling the actress he “totally” agreed with her.
Jane’s last appeared in a Playboy shoot last year, in which she wore silk lingerie accompanied with an oversized pastel peach jacket.
James Martin’s Saturday Morning airs today on ITV from 9.25am.